Trick or Trail. Halloween was a celebration of the great work from partners across the region to open Kenilworth Garden Section of the Anacostia Riverwalk Trail. This final section means there's now 70 miles of connected trails in the region. You can take the trail into Maryland along the Anacostia Tributary Trail and Northwest Branch Trail, as far north as Brookside Gardens in Wheaton MD, or east to Greenbelt Park. The trail connects to the south on the Anacostia Riverwalk Trail to Nationals Ballpark.